//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2012 EMC Corp.
//
//	@filename:
//		CParseHandlerColStats.h
//
//	@doc:
//		SAX parse handler class for parsing base relation column stats objects
//---------------------------------------------------------------------------

#ifndef GPDXL_CParseHandlerColStats_H
#define GPDXL_CParseHandlerColStats_H

#include "gpos/base.h"
#include "naucrates/dxl/parser/CParseHandlerMetadataObject.h"

// fwd decl
namespace gpmd
{
	class CMDIdColStats;
}

namespace gpdxl
{
	using namespace gpos;
	using namespace gpmd;
	using namespace gpnaucrates;

	XERCES_CPP_NAMESPACE_USE

	//---------------------------------------------------------------------------
	//	@class:
	//		CParseHandlerColStats
	//
	//	@doc:
	//		Parse handler class for base relation column stats
	//
	//---------------------------------------------------------------------------
	class CParseHandlerColStats : public CParseHandlerMetadataObject
	{
		private:
		
			// mdid of the col stats object
			CMDIdColStats *m_mdid;
			
			// name of the column
			CMDName *m_md_name;
			
			// column width
			CDouble m_width;
			
			// null fraction
			CDouble m_null_freq;

			// ndistinct of remaining tuples
			CDouble m_distinct_remaining;

			// frequency of remaining tuples
			CDouble m_freq_remaining;

			// is the column statistics missing in the database
			BOOL m_is_column_stats_missing;

			// private copy ctor
			CParseHandlerColStats(const CParseHandlerColStats&);

			// process the start of an element
			void StartElement
				(
				const XMLCh* const element_uri, 		// URI of element's namespace
 				const XMLCh* const element_local_name,	// local part of element's name
				const XMLCh* const element_qname,		// element's qname
				const Attributes& attr				// element's attributes
				);

			// process the end of an element
			void EndElement
				(
				const XMLCh* const element_uri, 		// URI of element's namespace
				const XMLCh* const element_local_name,	// local part of element's name
				const XMLCh* const element_qname		// element's qname
				);

		public:

			// ctor
			CParseHandlerColStats
				(
				CMemoryPool *mp,
				CParseHandlerManager *parse_handler_mgr,
				CParseHandlerBase *parse_handler_base
				);
	};
}

#endif // !GPDXL_CParseHandlerColStats_H

// EOF
